Engine



June 4, 1946. w. G. GERNANDT ENGINE Filed Feb. 28. 1944 s sheets-sheet 1m \"mw #magy/ l June 4, w. G. zaERNsmD-rA ENGINE Filed Feb. 28, 1944 3Sheets-Sheet 5 Patented .nlune '4, 1946 NT oFFlcEj ENGINE Walde G.Gewenst, Detroit, Mien., assigner to Briggs Manufacturing Company,Detroit, Mich., a corporation of Michigan Application February 28, 1944,Serial No. 524,165

' 1s claims. (cl. 12s-so) This invention relates to internal combustionengines and particularly to the type of engine inwhich a rotatable valveis provided for controlling the intake and exhaust and the firing of thecombustible mixture.

The present invention is particularly applicable tov an internalcombustion. engine of the kind in which the rotatable valve in the head,preferably although not necessarily rotatable continuously in onedirection, is formed with substantially all or at least the maiorportion of the combustion chamber at the time of firing and is generallyconical or truste-conical in shape, The combustion chamber within therotor or rotary valvehas an opening at one end leading to the cylinderand a second opening preferably at a sidethereoi to communicate duringoperation with an outlet or inlet passage, or bothv v as tbe'casemaybegand the combustible charge within the combustion chamber is medpreferablybysparkignition. Hanydimculties -are encountered. in theproduction of a satisfactoryengine ofthe vforegoing. typolone of the`moet serious being-in connection' with the lubrication of therotaryvalve andin 'other objects of thisl invention wm appear in ingsforming a part ofthis specication wherein like reference charactersdesignate correspond- `ing parts'in the several views.

the consumption-of lubricating eik Not only is `it important that properlubrication of the lvalve be provided butalsov thatthe valve beconstructed so 'as to preclude building up oLexcessb/eV pres-- sures atcertain loca1ities, due to thermal expan"L sionof the valve, tending todestroy the oil'lm. It is also important that provision be made foradequate delivery of oil at localities where the greatest load occursduring; operation.; 'A further important consideration, additional toadequate lubrication and control ofvalve expansion, is the pressure sideofthe valve'bearingsurface'in the cylinder head and spread in a iilmover the bearpiston.

A further object of the invention is to.pro A vide an improved valveconstruction whereby excessive friction between the valve and cylindering clearances between the valve achieved during operation,

the following description and appendedclaims, reference beinghad to theaccompanyim draw- Fig. lis a fragmentary sectional elevationillustrating a portion of a multi-cylinder engine emthrough lines-1 2bring. 1 100km 1n the direc;

tion of the arrows.

Fig. 3 is a fragmentary side lelevation illustratil ing one ofthe'cylinder heads.

substantially through lines 4 --4l of Fig; 3.1ookins in the directionrof the arrows.l

matter of oil consumption which in itself presents a serious problemowing to the tendency to excessive oil consumption consequent` to theuse of rotary valve constructions.

One of the objects ofthe present invention is to provide a lubricatingmeans for a rotatable valve of the above type of engine which will bemore eiilcient and accurate thereby improving' the operation of theengine and reducing oil con..

sumption.

A furtherobject of the invention is to control thedelivery of oil to therotatable valve so that adequate lubrication will be available atdesired localities while at the same time providing for the removal ofexcess oil not needed for lubrication purposes. l l

Still anotherobject of the invention is to provide improved lubricatingmeans for the valve by which lubricating oil is introduced at the highFig. 5 is e fragmentary view faken' substantie" inthe direction fromlines V5-4-5 of Fig. 4 looking of the arrows. j

Fig. 6 isal view similarto Fig. 4'illustrating, a further embodimentofthe' invention, g

Fig. 7' is a fragmentary view taken substantially from lines 1 1 of Fig.6 looking inthe direction of the arrows.

Fig. 8 is a. fragmentary sectional view, in part e' .diagrammaticaLillustrating clearances between the Vvalve and cylinder head, the samevbeing v somewhat exaggerated for the purpose of showing more clearly thefeatures of this construction..

Fig. 9 is a'view similar to Fig.' 7 illustrating another embodiment'ofthe invention. Before explaining in detail the present invention it isto be understood that the invention is not limited in its application tothe details of construction and' arrangement of parts illus-` trated inthe'ac'companying drawings, since the invention is capable of otherembodiments and e Fig. 4` is an enlarged fragmentary section .taken y 4l time of firing, is formed within the valve.

asomar or terminology employed herein is for the purpose of descriptionand not oi limitation.

In the drawings there are illustrated, by way of example, certainembodiments of the present invention asapplied to an internal combustionengine of the spark ignition type which may be used for the powerplantof an aircraft or motor vehicle or for other purposes, such as formarine and industrial engines. For most usesthe engine is of themulti-cylinder type, although any number of cylinder units may beemployed in any given engine. In the4 present embodiments,

for the purposes of simplicity, a single .cylinder unit of the engine,is illustrated, it being understood that the remaining cylinders of theengine are substantially identical to the structure herein shown' anddescribed.

Referring to Fig.. y1, the present engine comprises a suitable crankcase20 carrying a cylinder 2| within which a piston 22 is mounted forreciprocation. A crankshaft (not shown) is supported in suitablebearings in the crankcase accordingV to conventional practice and thepiston is connected to the crankshaft by a connecting rod 23.

The present engine, for the purposes of illustration, is of the liquidcooled type and-accordingly, the cylinder 2i is mounted within acylinder jacket 24, the lower end of whichV is brazed or otherwisesecured to the -crankcase y2li. Be-

' y.tween the .cylinder jacket 24 and the cylinder is a liquidl coolantchamber 25. yThe enginevfalso comprises a cylinder head 26 having a.tapped hole into which the upper end ofthe cylinder threadedqaut 26a.The cylinder head `is c ast to-provide a' depending. cylinder lheadJacket 21 V- yforming aliquid coolant chamber 28 'communieating with thechamber. The lower thickened edge of the cylinder lhead Jacket 2.1. isprovided with an annular groove within which is received a resilientrubber sealing .ring 29 engaging the upper outer wall of the'cylinderjacket 2B and placed under compression when the upper lend of thisjacket is forced into position, as shown,

. within the opening at the lower end of the cylinder head jacket. Thesealing ring 29, being pressed tightly against the cylinder jacket 24,

provides a liquid tight seal against leakage of the dium. "I'his chamberis sealed at its upper endby means of an expansion plug or disk d2mounted within a bore in the projecting `stem 43 of the valve.

As more particularly illustrated in Fig. 8, the outer wall of the valve33 is relieved circumferentially at dit. This relief area preferablyextends substantially entirely around the valve in the height of theside port 35. In the illustrated embodiment the height of thiscircumferential relief 'area 44 corresponds substantially to theheightof the side port 35. It will be noted, as shown in Fig, 8, thatthis relief area increases somewhat in depth from the upper to the loweredge thereof. Also it will be noted that immediately above the upperedge of this relief area 4l the outer wall of the valve is slightlyrelieved at 4,5, but this latter relief diminishes to a point where theclearance between the valve and wall ofuthe valve housing 3| does notexceed an` ordinaryrunning or operatingclearance. Below the lower. edgeof, the relieved-area 44 the valve wall providedwith a .circumferentialrelieved area 46 normally providing, when y.the valve is cold, av,clearance with respectl tothe adjacent wall of the valve housing 3l,whichmay exceed a normal running or operatingclearanceby one to one 'andone-half thousandths of an inch. Below the relieved areaV 46, which areaextends continuously around the valve immediately below the side port35, the wall "of the valve is additionally relieved toprovide an annulartapered or bevelled area 41 extending entirely around the valve andhaving a clearance at its'lower edge 41a with respect to the wall of thevalve coolant from the communicating chambers 25, 28. v

The lower end of the cylinder 2l, in the present embodiment, has asliding fit within an opening in the crankcase `2l) and the Jointbetween the cylinder and crankcase svsealed by means of sealing rings39.'

The cylinder head 26 is formed with a valve housing 3i, largelysurrounded by the coolant chamber 28 and provided with a generallyfrustoconical cavity 32 within which is rotatably mounted a generallyfrusto-conical valve 33, it being understood that the outer taperingwall of the valve corresponds generally to the shape of the juxtaposedwall oi the cavity 32. The valve 33 is provided with ay combustionchamber 34 having a bottom port 3S, arranged in constant Y communicationwith the cylinder, and a side port 35 adapted to register' insuccession, during rotation of the valve, with a spark plug 37 at thespark plug'locaton 39, an exhaust conduit 39 in the cylinder head, andan intake conduit 40 also inthe cylinder head.

The piston 22 is preferably formed at its outer end with a taperedportion which projects into housing 3i, which may` exceed 'an ordinaryrunning or operating -clearance by some four thousandths to sixthousandths of an inch. The bottom surface 33a of the valve 33 has anupward inclination or taper corresponding to the taper of the topsurface ofthe piston. 'I'his bottom inclined or tapered surface 33a ofthe-valve terminates in an annular upwardly extending bevel or taper edwhich, las shown in Fig. 8, terminatesat the lower edge 41a of therelieved area di'. It will be seen from Fig. 8 that the corner or.juncture lila of the tapered surfaces 4l and 48 is normally spacedinwardly from the upper edge o the cylinder 2l which has an annularbevel 49 at this locality. Although the above described -relieved areasare preferably provided in the wall.

of the valvev 33, it will be understood that one or more thereof may beformed in the wall 32 of Les valve housing 3|, and in particular therelieved area 44 may be constructed and serve the purposes` inaccordance with copending application Serial No. 495,260, iiled July 19,1943.

In laccordance with the present invention l means is provided forlubricating the vbearing surfaces of the valve 33 and the valve yhousing3| below the side port 3E and the annular relief 44 in the valve.Referring to Figs. 2 to 5 inclusive,

the cylinder head at a pointbetween the exhaust passage 33` and intakepassage di! and closer to the former is drilled, counterboredand tappedto provide an opening 5I! into which is connected an oil inlet pipe Ithrough which lubricating oil is introduced under suitable pressure byany conventional oil pump connected to a source of sup- Ply. Extendingfrom the inlet opening 50 is an inlet passage 50a which in turncommunicates with a smaller drilled hole 52 leading to a Dort v 53opening through the inner wall 52 of the valve housing 3|, ,4 The inletport 55 ispreferably located at a point near the lower end of the valverelief 45 but above the bevelled or tapered relief area 41 inthevalve,'as shown in Fig. 8. The inlet port 53 communicates with an angularly extending distributing oil groove 54 which' end of a drilled hole55 forming an outlet passage through the wall of the valve housing. The1 passage or duct 55 terminates in an enlarged tappedhole 51 into whichis secured the threaded end of e,4 coupling to which is connected a pipe58 leading to a vacuum pump 59 or other source of suction or reducedpressure. As hereinafter described, suction induced by the -pump 55 inthe suction line 55-58 will withdraw excess oil entering the oilpressure groove 54 ,from theinlet pressure line 50-52.

In the event it is desired to supplement the passage 56 and withdrawlubricating oil from the bearing surfaces at any desired point or pointscircumferentially spaced from the groove 54 and port 55,v additionalmeans may be provided for this purpose as illustrated in Figs. 6 and 'land also in Fig. 2. In this embodiment the wail of the valve housing isprovided with angularly` related divergingoil collector'grooves 55 and5l positioned in the height of the groove 54 andcircumferentially spacedtherefrom at any desiredl distance. A similar pair'of divergingcollector grooves 52 and 53 may be provided at a suitable Adistance fromthe grooves 50 and 5I, and both pairs, as shown in Fig.y '1,' connectedby a communicatinggroove 54 leading to a port 55 at the end of a drilledoil passage 55 communicating with A the outlet opening 51. Thus, duringoperation of d the vacuum pump 55. the suction induced in the formedinthe wall of the valve housing 3| above Fig. 9 an adextends upwardly inthe wall 32 of the valve'housving and'terminates in an outlet port 55at'the 15T and below the oil pressure groove 54 and at a suitabledistance therefrom. These grooves 51 and 55 'will lie near the upper andlower edges ofthe relieved area "in the valve and may extend insubstantially parallel relation as shown in I"ig.'9. The collectorgrooves 51 and 55 com# municate with drilled oil-passages 55 and. whichin turn communicate with the opening 51 so that suction induced in theline 55 will. cause oil to be withdrawn from the collector grooves 51and 5l.v

The valve. is driven at one-half engine or crankshaft speed through themedium of the projecting stem 45. Such driving mechanism for the valveis more fully shown and described in my January 15, 1944. The valve isyieldinglyheld up wardly within the frustofconical recess l! in the i 6erted by the spring to raise the valve within the valve housing issuillcient to substantially offset or equal the effort exerted duringthe suction stroke of the piston to draw the valve downwardly and awayfrom its seat. d

It will be understood that other suitable source of suction or reducedpressure than the pump 59 may be provided, and that the oil withdrawnfrom the collector grooves and distributing groove is returned to theoil sump or source of supply and thence returned tothe bearing surfacesby the usual oil pump. The oil grooves are located at the pressure sideof the valve oppostethe spark plug at the .locality where the'greatestload comes at the time of firing, thus ensuring maintenance of anadequate oil film at Vthe bearing surfaces most subject to friction andscoring duringoperation. By using a scavenge p uxnp 59 to withdrawexcess `oil itis possible, and preferred, to produce a suction effort ornegative pressurein the oil exhaust conduit 58 at all times somewhat inexcess than the maximum suction effort or negative pressure in thecylinder during the suction stroke of the piston, especially whenrunning idle. This enables excess oil to be returned by the pump to theoil sump rather than be drawn into the cylinder `and as a consequencereduces oil consumption materially. d

It vwill be seen that a circulation of oil to and from the valve bearingsurface is maintained while `at the same time control of the amount ofoil actually delivered `to and spread over the bearing surfaces by thewiping action of the valve is also ensured. It is desirable that the oilbe delivered through duct 52 and. flow into'and through thedistributing" groove 54 under pressure, or in other words that a,pressure circula- "tion of Voil through all passages andgrooves bemaintained, thereby preventing the accumulation or formation of carbontending to clog the passages. It is also important that the distributingand collector grooves be connected to a source of reduced pressure orsuction so as .not-only to A maintain a circulating flow of oil but alsoto withdraw excess oil from the bearing' surfaces. With thisconstruction, namely, the use of a suction system to enhance circulationof oil it is possible to more accurately control the oil nlm, the

amount of o il actually distributed over the bear- 'ing surfaces, andthe consumption thereof.

It will be understood that the size and length of the oil grooves andtheir respective positions will be governed by the requirements anddesign -copendin'g applicationY Serial No. 518.323, filed valve housingby means of aV compression spring 1i which is held under constantcompression against a steel coupling disk 'I2 which in turn is heldinplace by a nut 15 engaging a bolt 14 of the particular engine, thepresent construction being shown for illustrative purposes.

Y The annular relief areas 45 `and 41 are im portant in ena-bling properlubrication to be maintained and preventing destruction crimpairme'nt ofthe oil film during operation. These relief areas. which. may be termedexpansion re liefs, offset expansion of the valve outwardly towardV thevalve bearing surface of the cylinder l such that when the valve ishottest during operation andmaximum expansion thereof `has occurred, thevalve surfaces will have substantiallyv a normal running or operatingclearance throughout these areas with the bearing wall Il of thecylinder head. The relief area M extending in the height of the valve ispreferably of a depth to permit carbon to form therein, so that aftercontinued operation this relief will be filled with carbon and providean excellent bearing not requiring any direct lubrication with oil. Thisconstruction and the advantages thereof are more particularly describedin the above mentioned copending application.

I claim: I

1. In an internal combustion engine having a cylinder, a body,alrotatable valve in said body associated with said cylinder and havinga combustion chamber therein. a conduit in said body for delivering oilto a groove in the valve bearing surface of the body, and a collectoroil groove in said surface spaced from said first named groove andconnected to a source of suction.

2. In an internal combustion engine having a cylinder, a body, arotatable valve in said body associated -with said cylinder and having acombustion chamber therein, a conduit in said` body for delivering oilto a groove in the valve bearing -surface of the body, a collectorgroove in said surface spaced from said first named groove, and meansfor connecting said collector groove and first named groove to a sourceof suction or suction.

3. In an internal combustion engine having a cylinder, a body, arotatable valve in said body associated with said cylinder and .having acombustion chamber therein, a conduit in' said body for delivering oilto a groove in the valve bearing surface of the body, and a collectoroil groove in said surface spaced from said first named groove in adirection circumferentially of the 5. In an internal combustion enginehaving a cylinder, a cylinder head, a rotatable generally frusta-conicalvalve in `said head having a com.` bustion cham-ber and a side portcommunicating.

therewith, an oil inlet conduit in said head for delivering cil to thevalve. a distributing groove in the valve bearing surface of the headconnected to said conduit, and conduit means con nected to a source ofsuction or reduced pressure and communicating with said groove belowsaid port, said groove being located below saidport and above the loweredge of thevalve.

6. In an internal combustion engine having .a

increasing depth toward said widerend, said relieved area comprisingportions ofdifferent depths, the portion of greatest depth extendingaround the valve proximate to the cylinder.

8. In an int'ernal combustion engine having a' cylinder, a cylinderhead, a rotatable generally frusta-conical valve in said head having acombustion chamber and a side port communicating therewith, said valvevhaving a circumferential relieved area below said port of increasingdepth terminating in an annular bevel forming an expansion relief ofgreater depth than said relieved area.

9.. In an internal combustion engine having a cylinder, a cylinder head,a rotatable generally frusto-conical valve in said head having a com- Ibustion chamber and a side portv communicating therewith, said valvebeing positioned with its wider end adjacent the cylinder and having acincumferential relieved area below said port of increasing depth towardsaid wider end, and means l1. In an internal combustionengine having a.

cylinder. a cylinder head, a rotatable valve in said head associatedwith the cylinder, said head having abearing surface for the valve andoil inlet and outlet conduits, and oil groove means in said surfaceopening toward the valve and connected to said conduits at points spacedaxially of the valve intermediate the ends thereof.

12. In an internal combustion engine having a cylinder, a body, arotatable valve in said body associated with said cylinder, Lan oilgroove in the body opening toward the valve for distributing oil to acircumferential area of the valve bearing surface of the head extendingin the height of said groove, means for delivering oil to said groove,and means for withdrawing oil from the valve bearing surface within saidarea. i

13. In an internal combustion engine having a surface of the headextending in the height of.

said groove, means for delivering oil to said groove,

and ,means for withdrawing oil from the valve bearing surface at alocality spaced from said cylinder, a cylinder head, a rotatablegenerally frusto-conical valve in said head having a combustion chamberand a side port communicating therewith, said valve being positionedwith its wider end adjacent the cylinder and having a circumferentialrelieved area below said port of increasing depth toward saidwider'end.`

7. In an internal combustion engine having a cylinder, a cylinder head,a rotatable generally frusto-'conical valve in said head having acombustion chamber and aside port communicating therewith, said valvebeing positionedwith its wider end adjacent the cylinder and having a4circumferential relieved area belowsaid port of groove circumferentiallyof the valve.

.at a point or points spaced fromsaid groove axially of the valve.

15; In an internal combustion engine having a cylinder, a body, arotatable -valve in said body associated with said cylinder, an oilgroove in theA body opening toward the valve for distributing oil to acircmnferentisl area of the valve bearing suriaee of the head extendingin theheight of said groove. an oil inlet conduit for delivering oil tosaid groove, and conduit means for conveying oil from the valve surfacewithin said area.

16. In an internal combustion engine having a cylinder. a body, arotatable valve in said body associated with said cylinder, an oilgroove in the bodyl opening toward the valve for distributing oil to ncircumferential area of the valve bearingr lo surface of the headextending in the height of said groove, an oil inlet conduit fordelivering oil to said-groove, and conduit means for conveying oil fromthe valve surface within said areaat a locality spaced from said groovecircumferentially 13 ofthevalve.

17. Inan internal combustion engine having a cylinder. a body, arotatable valve in said body associated with said cylinder. an oilgroove in the 10 body opening toward the valve for distributing oil to acircumferential ares of the valve besrinz surface o! the head extendingin the height of saidv groove, an oil inlet conduit for delivering oilto said groove at a predetermined point, and conduit means for conveyingoil from 'the valve bearing surface at points at opposite sides of saiclpoint of delivery.

18. In an internal combustion engine having a cylinder. a body,'arotatable valve in said body

